Carb Issues?

[ramz]

Wanted to get some opinions on my issue. My truck starts up on first try in the mornings but seems when it been running a while (driving around town and such) it takes longer to start up. Could this be the carb?

[veinbar]

Originally Posted by ramz

Wanted to get some opinions on my issue. My truck starts up on first try in the mornings but seems when it been running a while (driving around town and such) it takes longer to start up. Could this be the carb?

Does it turn over slower than usual (does it seem to drag?) or does it turn the motor same as in the morning?

[ramz]

It turns over the same as in the morning just takes longer to start like its flooded. I might have to turn the key for 4-5 sec twice to start.

[Rons86]

What king of motor and carb/intake are you running?

[ramz]

305 with 4 barrel carb with stock intake.

[76stepsidechevy]

Do you pump the gas when you try to start it after recent driving? Mine always seems to start easier when I dont give it gas.

[tucsonjwt]

When the truck is warm and you try to start it, hold the accelerator all the way to the floor and keep it there as you turn the key to start the truck. When the truck starts to "catch", keep your accelerator all the way down for an extra second or two (reving the engine), then let up on the accelerator. If you have vapor lock this will allow the engine to start. Vapor lock has different "fixes", like adding a spacer block under the carb, but I just deal with it as described above since I have a big block and they tend to vapor lock and I don't want to mod the carb.

[ramz]

Thanks for the replies. My Carburetor has been rebuilt about 3-4 years ago but truck sat around for about a year. I was thinking about buying a new one along with a throttle body spacer. After some research about vapor lock I found this.......

Your symptoms are those of a leaking carburetor, flooding the intake manifold with gas. The fact that the accelerator pump chamber still has gas in it doesn't mean that the main bowl is still full. My guess is that there is leakage inside the carburetor, drowning the engine until you crank through enough air to blow it clear so the mixture can get back to normal. To prove this, run the car until it is thoroughly warm, then shut it down and quickly remove the carburetor from the intake manifold without tipping if over, so that it does not spill any gas, then set it on a clean dry paper towel on your workbench. Come back in an hour or so, I'm betting you will see and smell gas on the towel.

Another way to prove this to yourself is to let the car sit for an hour or so after you turn it off, then open the hood, lift off the air cleaner, and smell down into the carburetor - I'm betting you will smell gas down there, and maybe even see liquid gas on the throttle blades.

Carburetors which have been through the rebuilding process often develop this problem, as the cleaning chemicals remove the sealing coating from the porous aluminum and pot metal parts. The only cure is to replace the carburetor with a new (NOT REBUILT!) carburetor.

[tucsonjwt]

I think the advice you reference is interesting, but saying you should only buy a new carburetor I think is in error. Many forum members have professionally rebuilt carburetors which are running fine. The only new carburetors are aftermarket, and I do not think the aftermarket carburetors match the quality of a professionally rebuilt Qjet. From everything I have read, and discussions I have had with many mechanics, Qjets have fuel leakage issues that develop from various places, but they have other advantages. This means they will likely need rebuild every few years, but so will the aftermarket new carbs - for other reasons. In my experience, aftermarket new carbs (Carter, Edelbrock, etc.) have not been trouble free and the quality of machining/matching of the parts were inferior to a stock Qjet. Each to his or her own.